High pressure presses have been used for decades in the manufacture of synthetic diamond. Such presses are capable of exerting a high pressure and high temperature on a volume of carbonaceous material to create conditions for sintering polycrystalline diamond. Known designs for high pressure presses include, but are not limited to, belt press type designs, tetrahedral press type designs, and cubic press type designs.
FIG. 1 shows a basic design for a conventional cubic press 10 known in the art. The design generally includes six press bases 12, with each press base 12 facing towards a common central region 14. Each press base 12 includes a piston cavity 13 (shown in dashed lines) that houses a piston 16. The cubic press 10 also comprises a series of tie bars 18 that extend between adjacent press bases 12 to add stability to cubic press 10.
During operation of cubic press 10, a piston 16 is thrust out of a piston cavity 13 in each press base 12 towards common central region 14. As pistons 16 move forward towards common central region 14, pistons 16 apply pressure to each side of a cubic volume of carbonaceous material located generally at an around common central region 14.
Various components of cubic press 10 are put under stress as a result of counter forces created in response to pressure being applied to the cubic volume of carbonaceous material located generally at common central region 14. For example, press bases 12 are subjected to forces during cubic press 10 operation that can lead to deformation of press bases 12. Such deformation, in turn, results in high stress fields in various components including the lower part of piston cavities 13. Over time and after numerous cycles, cracks may begin to form in the lower part of piston cavities 13, eventually shortening the fatigue life of press bases 12 and cubic press 10.
It would be advantageous to provide an improved press base of a high pressure press and a method of improving a press base of a high pressure press.